1. Field of the Invention
The embodiments of the invention generally relate to a lift having an articulated linkage assembly.
2. Background of the Related Art
Articulated linkage assemblies have long been utilized for moving objects and/or providing a mechanical advantage. In its simplest form, an articulated linkage assembly consists of a first linkage rotatably coupled to a second linkage. The movement of the second linkage relative to the first linkage provides a range of motion that can be utilized, for example, to move an object held in a gripper coupled to the second linkage. Examples of such linkages are commonly found in robotic applications, wherein the movement between the linkages is controlled by actuators such as pneumatic cylinders or electric motors. Alternatively, the relative movement of the linkages may be controlled manually.
Although the use of articulated linkages is widespread, the utilization of conventional articulated linkages in cleanroom applications presents special problems. For example, actuators, bearings and linkages often introduce particulate into the cleanroom that may adversely affect semiconductor wafer processing. Additionally, articulated linkages commonly utilized to move large and/or heavy objects are bulky and cumbersome and pose a threat of damaging delicate semiconductor processing equipment through incidental contact. Moreover, the erection, use and disassembly of such articulated linkages utilized to maneuver heavy objects within the cleanroom often requires multiple personnel due to the weight and complexity of the linkage assembly and disassembly process. In light of the sensitivity to particle generation associated with persons in the cleanroom and the time and expense associated with having persons engaged in activity within the cleanroom, the minimization of personnel required to erect, operate and disassemble such linkages within the cleanroom is highly desirable.
Therefore, there is a need for an improved articulated linkage for cleanroom applications.
A cleanroom lift for maneuvering large objects such as turbomolecular pumps utilized in semiconductor processing applications is provided. In one embodiment, a cleanroom lift includes a vertically movable carriage coupled to a linkage assembly. The linkage assembly has a first link and a second link. Each link has one piece construction to minimize deflection under load. The first link is coupled to a carriage shaft assembly and a linkage shaft assembly. Both shaft assemblies have preloaded bearings. The second link is coupled to the linkage shaft assembly and a gripper assembly. Optionally, the gripper assembly is coupled to a third link by a second shaft assembly to minimize the weight of the links to facilitate assembly and disassembly in cleanroom environments. The coupling of the links is generally facilitated through the use of shaft clamps that allow the bearings and shaft assemblies to remained aligned when disassembled. This allows the linkage assembly to be easily disassembled, transported and assembled by one person thereby facilitating use in a cleanroom environment.